Bryngwyn Colliery Engine House

Two-window ruined engine house of 2 storeys and a plinth. The roof, N wall and part of the W wall are no longer extant. Constructed of coursed rubble sandstone with raised quoins and grey brick facings. Round-headed openings with voussoirs, raised keystones and imposts, and stone sills. Some of the heads are badly eroded, whilst the lower openings may have been enlarged to remove the machinery. The S end of the building has one large opening to each storey. High plinth constructed of larger stones. Tie rods pass through the engine house at 1st floor level, 2 through the S end and 1 through the N end, with circular tie plates.

The cylinder bed is on the N side of the interior at ground floor level, with a pit in the S half within the plinth. Wide round arched openings of large voussoirs provide access through the S wall of the plinth, and beneath the cylinder bed to the N. Horizontal rods are said to have passed through these, those to the S attached to the pump rods, and those to the N connected with a balance box. Round-headed openings in E and W sides of the plinth similar to those above, all with yellow brick soffits. Four large sockets in S wall of plinth at shoulder height of round arch, and also at 1st floor sill level. Further sockets to N end of internal E wall at 1st floor level. Joist holes to 1st floor.